Connective Tissue I Flashcards
1
Q
describe fibroblasts
A
- Most common cell in connective tissue
- Synthesize fibers and ground substance
- Myofibroblasts: wound healing and presence of contractile filaments
2
Q
describe the 2 pictures
A
- top: adult fibroblasts
- large oval nucleus
- spindle shaped basophilic cytoplasm
- active protein synthesis
- bottom: fibrocytes
- collagen synthesis stops
- lose basophilic cytoplasm
- nucleus shrinks
3
Q
A
EM of fibroblasts
Collagen fibrils can be noted outside the cell
4
Q
describe brown fat
A
- many lipid droplets
- rich in mitochondria
- highly vascular
- main function: heat production
5
Q
describe macrophages
A
- derived from monocytes–migrate to connective tissue, differentiate to macrophages
- irregular cell membrane/cytoplasmic extensions (pseudopodia)
- phagocytic; produce cytokines
- antigen presenting cells; multinuclear giant cells
6
Q
A
- Macrophage
- prominent Golgi
- abundant lysosomes breakdown of phagocytic materials
- numerous phagocytic vesicles (or phagosomes) for the storage of ingested materials
- nucleus has an irregular outline
7
Q
describe mast cells
A
- originate in the bone marrow from precursor cells lacking cytoplasmic granules
- when they migrate to connective tissue or lamina propria of mucosae, they proliferate and accumulate cytoplasmic granules
- mast cells and basophils circulating in the blood are derived from the same progenitor in the bone marrow
8
Q
A
EM of mast cell
- granules containing histamine and heparin
9
Q
describe lymphocytes
A
- small, spherical cell with a scant cytoplasm
- condensed, basophilic nucleus
- immune cells – B and T cells
- B-lymphocytes develop into plasma cells
10
Q
A
lymphocytes
11
Q
describe plasma cells
A
- plasma cell is derived from the differentiation of B lymphocytes
- synthesizes and secretes single class of immunoglobin
- immunoglobins are glycoproteins
- Basophilic cytoplasm (increased rER)
12
Q
A
plasma cells
13
Q
describe eosinophils
A
- eosinophilic (red) granules in the cytoplasm
- condensed, bi-lobed nucleus
- phagocytosis of antibody-antigen complexes
14
Q
A
eosinophils
15
Q
name the distribution of collagen
A
- Type I collagen
- bone, tendon, dentin and skin
- Type II collagen
- hyaline and elastic cartilage
- Type III collagen
- reticular lamina of basement membrane as a component of reticular fibers
- Type IV collagen
- basal lamina. Each molecule binds to binding site of laminin
- Type V collagen
- aminon and chorion in the fetus, muscle and tendon sheaths
- aminon and chorion in the fetus, muscle and tendon sheaths
17
Q
A
- loose (areolar) connective tissue
- fills space between other tissues - large number of cells
- flexible, rich blood supply, not resistant to stress
18
Q
A
- dense irregular connective tissue
- fewer cells, more fibers than loose tissue
- no orientation of collagen fibers – resistance to stress in all directions
- organs capsules, periosteum, dermis
19
Q
A
- dense regular connective tissue
- specific orientation of collagen fibers
- tendons/ligaments
- imparts tensile strength
20
Q
A
- reticular connective tissue
- reticular cells (modified fibroblasts) – cytoplasmic extensions cover reticular fibers
- frame work for myeloid (bone marrow) and lymphoid (lymph nodes, speen) organs
21
Q
A
- PAS staining of reticular connective tissues
22
Q
A
- elastic connective tissue
- elastic fibers - yellow colored
- ligamentum flavum, vocal ligament, suspensory ligament of penis
23
Q
A
- elastic stains highlights the large number of elastic fibers in aorta
24
Q
A
- white adipose cells
- cells are large
- nucleus is peripheral
- lipid droplet is one
- function is fat storage
25
Q
A
- brown adipose tissue
- cells are smaller
- nucleus is central
- lipid droplet is many
- function is energy release
